Microplates have become the standard sample container for laboratory testing, taking over the role previously occupied by test tubes and plastic tube arrays. The flat matrix style microplate format is adaptable to a wide range of sample volumes, is convenient for large numbers of samples, and lends itself to various methods of analysis. Microplates are continually evolving and have been constructed of thin film continuous plastic sheets allowing a vast number of plates to be rolled up in a very small volume that contain millions of samples.
Microplate readers primarily comprise optical measurement devices that use standard analytical techniques to probe a sample in a microplate well of a microplate. The samples in the microplate well have intrinsic properties that can be measured using these optical and analytical methods. The samples, or chemicals that can interact with the samples, may alternatively be tagged with compounds or molecules that can be probed using the microplate reader. Exemplary core optical techniques commonly used in microplate readers include: absorbance (ABS), Fluorescence Intensity (FI), luminescence (LUM), Fluorescence Polarization (FP), Time-Resolved Fluorescence (TRF), Fluorescence Lifetime (FLT), Fluorescent (or Förster) Resonance Energy Transfer (FRET), Time-Resolved FRET (TR-FRET), Bioluminescence Resonance Energy Transfer (BRET), nephelometry, Surface Plasmon Resonance (SPR), Alpha Technology (AlphaScreen™, AlphaLISA™), Raman scattering, turbidity (Mie scattering, Rayleigh scattering), and combinations of these, but any analytical optical technique can be adapted to a microplate reader.
While a number of microplate reader designs are available, many have proven unsuitable for some task(s). As such, there remains a need for alternative microplate reader designs.